updated 03/03/2008 AT 01:00 AM EST
•originally published 03/03/2008 AT 01:00 AM EST
LES DEUX, L.A., FEB. 12: Rihanna knows how to throw a party. The singer, who rang in her 20th b-day with Kanye West and Wilmer Valderrama, was slinging cupcakes at rumored beau Chris Brown—and he threw back! "There was frosting all over her face," says a source. Brown sang "Happy Birthday" to RiRi, but that may not have been his only gift. Recently, Brown snagged a $60,000 diamond and pink sapphire necklace and a $50,000 ruby and diamond heart pendant (above) at Jason of Beverly Hills.
Rumer Willis hit nightspot Villa and then the bricks Feb. 18—they asked her to leave because she's not 21.... Nicole Richie, Joel Madden and his brother Benji toasted a pal's birthday at Teddy's Feb. 16.... At a Feb. 13 benefit at Fendi, Mandy Moore admitted "singing 'Papa Don't Preach' [as a kid], but I called it 'Papa Dog Preach.'" ... Tina Fey lamented her workout routine at a magazine gala Feb. 12: "I thought I'd come back from the writers' strike really ripped, but I think I worked out three times."
A HERO TURNS 50
Jack Coleman's birthday bash could have easily been a cast party. Hayden Panettiere hit the Fifties-themed event, held at a private home in the Hollywood Hills Feb. 16, and was never far from boyfriend Milo Ventimiglia. Ali Larter curled up on fiancé Hayes MacArthur's lap, Masi Oka played the social butterfly while Zachary Quinto hung out poolside. Coleman trivia? He played a Carrington in Dynasty, which explains why Joan Collins was there, surrounded by male admirers. The most touching moment of the night? "The card that Hayden wrote to me was so sweet," says Coleman. "It brought tears to my eyes."